Method and System for Patella Tendon Realignment

ABSTRACT

A method and system provide and use a patellar implant. The patellar implant includes a superior portion, an inferior portion opposite to the superior portion, and an anterior portion. The superior portion being configured to reside below a patellar tendon and to elevate and/or tilt the patellar tendon. The inferior portion is configured to be seated in proximity to a tibia. The anterior portion is between the superior portion and the inferior portion. The anterior portion is placed in proximity to a patella. In one aspect, the method includes inserting the implant beneath the patellar tendon and between the patella and a position at which the patellar tendon is affixed to the tibia. In this aspect, the method also includes affixing the implant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 12/671,478, filed on Jan. 29, 2010, which is a national stageapplication of PCT Application No. PCT/US08/71629, filed on Jul. 30,2008, which claims priority to U.S. Provisional Patent Application No.60/953,325, filed on Aug. 1, 2007, each of which is hereby incorporatedherein by reference in its entirety.

BACKGROUND

Problems of the patella-femoral joint are a common cause of knee pain.The pain may arise from issues such as poor alignment of the patella orfrom cartilage breakdown (chondromalacia or arthritis) behind thepatella or on the opposing articular surface of the femoral groove(trochlea). Conventional surgical options for treating patella-femoralpain caused by malalignment, chondromalacia or arthritis may includerealignment of the patella. For example tracking of the patella may bechanged by tilting the patella or by moving the patella to one side orthe other. Moving the patella forward (i.e., anteriorly) through asurgical procedure provides another conventional option for treatingthese conditions. This conventional technique is thought to decreaseforce across the patella-femoral joint and thus diminish the painarising from excess force against a worn-out patellar or trochlearcartilage.

Although available, surgical options to realign the patella may be veryinvasive. For example, surgeries may involve cutting and fixating thebony attachment of the patellar tendon. In particular, conventionaltechniques may include detaching the patellar tendon from the tibia,then reattaching the patellar tendon at a new location to obtain thedesired alignment of the patella. Such invasive surgical techniques mayalso result in prolonged recovery times. Consequently, an improvedmechanism for treating patella-femoral joint problems such aspatella-femoral pain, chondromalacia, and/or arthritis is desired.

SUMMARY

A patellar implant and a method for using the patellar implant aredescribed. The patellar implant includes a superior portion, an inferiorportion opposite to the superior portion, and an anterior portion. Thesuperior portion being configured to reside below a patellar tendon andto elevate and/or tilt the patellar tendon. The inferior portion isconfigured to be seated in proximity to a tibia. The anterior portion isbetween the superior portion and the inferior portion. The anteriorportion is placed in proximity to a patella. In one aspect, the methodincludes inserting the implant beneath the patellar tendon and betweenthe patella and a position at which the patellar tendon is affixed tothe tibia. In this aspect, the method also includes affixing theimplant.

According to the method and system disclosed herein, the patellarimplant may be used to realign, for example by elevating and/or tilting,the patellar tendon. As a result, various the patella-femoral jointproblems may be alleviated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary embodiment of a patellar implant.

FIG. 2 depicts another exemplary embodiment of a patellar implant.

FIG. 3 depicts another exemplary embodiment of a patellar implant.

FIG. 4 depicts another exemplary embodiment of a patellar implant.

FIG. 5 depicts another exemplary embodiment of a patellar implant.

FIG. 6 depicts another exemplary embodiment of a patellar implant.

FIG. 7 depicts an exemplary embodiment of one option for placement of anexemplary embodiment of a patellar implant to reposition the patellartendon and patella.

FIGS. 8-9 depict another exemplary embodiment of a patellar implant.

FIGS. 10-11 depict another exemplary embodiment of a patellar implant.

FIG. 12 depicts another exemplary embodiment of a patellar implant.

FIG. 13 depicts another exemplary embodiment of a patellar implant.

FIGS. 14-17 depict other exemplary embodiments of patellar implantspositioned beneath a patellar tendon.

FIGS. 18-22 depict another exemplary embodiment of a patellar implant.

FIG. 23 depicts an exemplary embodiment of a method for placing apatellar implant.

DETAILED DESCRIPTION

The method and system relate to medical devices, particularly implants.The following description is presented to enable one of ordinary skillin the art to make and use the disclosed embodiments and is provided inthe context of a patent application and its requirements. Variousmodifications to the embodiments and the generic principles and featuresdescribed herein will be readily apparent to those skilled in the art.Thus, the method and system are not intended to be limited to theembodiments shown, but is to be accorded the widest scope consistentwith the principles and features described herein.

The method and system are mainly described in terms of particularsystems provided in particular implementations. However, one of ordinaryskill in the art will readily recognize that this method and system willoperate effectively in other implementations. For example, theparticular shape of the patellar implant may take a number of differentforms depending upon, for example, the specific anatomy of a patient andthe problem desired to be addressed. The method and system will also bedescribed in the context of particular methods having certain steps.However, the method and system operate effectively for other methodshaving different and/or additional steps not inconsistent with themethod and system.

FIG. 1 depicts an exemplary embodiment of a patellar implant 100. Forclarity, FIG. 1 is not drawn to scale. The patellar implant includes asuperior portion 102, an inferior portion 104, and an anterior portion106. The patellar implant 100 includes a posterior portion (not shown)that is opposite to the anterior portion 106. In the embodiment shown,the posterior portion is substantially the same as and parallel to theanterior portion 106. Also shown are lateral surfaces 108 and 110 aswell as edges 112 and 114.

The superior portion 102 is shown having a convex upper surface. Inaddition, the superior portion is symmetric. The superior portion 102 isto reside in proximity to the patellar tendon, while the inferiorportion 104 is to reside in proximity to the tibia. The inferior portion104 of the patellar implant 100 is substantially flat. The superiorportion 102 is thus configured to lift and/or tilt the patellar tendon,while the surface of the inferior portion 104 is configured to fit thetibia. The amount of lift and/or tilt provided may depend upon the shapeof the implant 100 as well as the positioning of the implant 100 in thepatient. Consequently, the size and/or shape of the implant 100 mayvary. For example, in some embodiments, the height, h, of the patellarimplant 100 may be between 0.5 and 3 centimeters. In other embodiments,the height may vary between 1 and 2 centimeters. In some embodiments,the width, w, of the patellar implant 100 may be between 1 and 3.5centimeters. In other embodiments, the width of the patellar implant 100may vary between 2 and 3 centimeters. Similarly, in some embodiments,the length, I, of the patellar implant may vary between one and 3.5centimeters. In other embodiments, the length may vary between 1 andthree centimeters. In other embodiments, other heights, widths, lengths,and/or angles between components may differ.

In use, the patellar implant 100 may be inserted through an incision inproximity to the patella. The patellar implant 100 is placed below thepatellar tendon (not shown in FIG. 1) between the patella (not shown inFIG. 1) and a distal attachment of the patella (not shown in FIG. 1). Inother words, the patellar implant 100 is placed between the patellartendon and the tibia and between the patella and a location at which thepatellar tendon attaches to the tibia. The location of the patellarimplant 100, as well as its particular configuration, is selected toachieve the desired tilt and/or elevation of the patellar tendon andthus the desired repositioning of the patella. In the embodiment shown,the inferior portion 104 is flat. As a result, a slot or flat region maybe formed in the tibia at the desired position of the patellar implant100. The patellar implant 100 is then fitted on the slot such that theinferior portion 104 meets the flat region of the tibia. Once thepatellar implant 100 is in the desired position, the patellar implantmay be fixed in place, through a variety of mechanisms, described below.In some embodiments. The patellar implant 100 may then be affixed to thetibia, the patellar tendon, or both.

The patellar implant 100 may include various materials. Particularembodiments may include natural materials, synthetic materials, or acombination thereof. For example, the patellar implant 100 or portionsthereof may be constructed using plastics, metals, synthetic bonematerials, allografts and/or other materials. Examples of representativematerials may include, but are not limited to, stainless steel,titanium, cobalt chrome, polyethylene, polyetheretherketone, and othermaterials. In some embodiments, the patellar implant 100 may be formedas a composite. For example the superior portion 102 may be made ofdifferent materials than the inferior portion 104. In anotherembodiment, the superior portion 102 and inferior portion 104 may bemade of the same material(s). However, in either embodiment, theportions 102 and 104 may be formed as separate pieces, then joinedtogether.

The use of different materials may allow the patellar implant 100 toadapt to the differential forces facing these surfaces. For example,composite patellar implant 100 may include a superior portion 102fabricated from a polymeric material, with a metal inferior portion 104.This allows the polymeric material of the superior portion 102 to be incontact with the patellar tendon, while a textured surface on the metalof the inferior portion 104 contacts bone. Other arrangements andcombinations might also be used. Coatings, adhesives, surfaces, and/orother features may be used, for example on the surface of the superiorportion 102 and/or the surface of the inferior portion 104. Suchtreatments may be provided to facilitate local affixation, growth of thetendon and/or bone to the patellar implant 100, healing, and/or otherdesired outcomes. As an example, a bone ingrowth surface using metalbeads, a bone morphogenic protein, or the like may be provided.

Although depicted with particular shape(s), the implant 100 and/or itscomponents may take any shape that is anatomically acceptable forpositioning beneath the patellar tendon and/or patella. For example,some edges of the patellar implant 100, such as the edge 112, is shownas being sharp. Other edges, such as the edge 114 are shown as beingrounded. However, the particular shape of an edge may be altered. Inanother embodiment, the edge 112 might be rounded and/or the edge 114sharp. Rounding of edges 112 and 114 may reduce stresses placed on theimplant 100 during physiological use. Similarly, the surfaces of theimplant 100 may be modified to conform to the anatomic position wherethe implant 100 is to be used. Thus, portions 102, 104, 106, 108, and110 may have different shapes, placements, and/or angles with respect toeach other. For example, although the superior portion 102 is shownhaving a symmetric, convex upper surface, the superior portion 102 mayhave a different shape. Other such shapes may include ridges that may beconfigured to position or adhere the patellar implant 100 to theportion(s) of the patient's anatomy. In other embodiments, ridges may beomitted. Similarly, the inferior portion 104 of the patellar implant isdepicted as substantially flat. However, in another embodiment, theinferior portion 104 may have a different shape. Further, althoughlateral surfaces 108 and 110 are shown, in another embodiment, thesurface 108 and/or 110 may be omitted, may not be planar, and/or mayhave a different shape.

Because the superior portion 102 elevates and/or tilts the patellartendon, the patella may be repositioned. For example, the patella may beelevated and/or tilted. Without being bound by theory, it is understoodthat the elevation and/or tilting of the patella may alter patellartracking and decrease forces on the patella, thereby treating patientswith patella pain, chondromalacia of the patella or patellarmalalignment. Consequently, pain and/or other issues related topatellar-femoral joint problems may be alleviated. For example, somepatellar-femoral joint problems are due to the patella contacting thetibia or femur. Elevating or tilting the patella a desired amount usingthe implant 100 may provide space between the patella and the tibia orfemur. The elevation of the patella may also decrease force loads acrossthe patellar-femoral joint. As a result patellar pain, malalignment,chondromalacia, arthritis, and/or other issues involving thepatellar-femoral joint may be treated.

FIG. 2 depicts another exemplary embodiment of a patellar implant 100′.For clarity, FIG. 2 is not drawn to scale. The components of thepatellar implant 100′ are analogous to the patellar implant 100 and are,therefore, labeled similarly. Thus, the patellar implant 100′ includes asuperior portion 102′, an inferior portion 104′, anterior portion 106′,and posterior portion (not shown in FIG. 2). Also shown are lateralsurfaces 108′ and 110′ as well as edges 112′ and 114′. As for thepatellar implant 100, the amount of lift and/or tilt of the patellartendon may vary between patients. Consequently, the size, anglesbetween, degree of rounding, and/or specific shape of the patellarimplant 100′ and portions 102′, 104′, 106′, 107, 108′, 110′, 112′, and114′ may also vary. Further, although lateral surfaces 108′ and 110′ areshown, in another embodiment, the surface 108′ and/or 110′ may beomitted. For example, the concave superior portion 102′ may simpleterminate at an edge 112′ that is adjacent to the inferior portion 104′.In addition, the patellar implant 100′ is used in a similar manner toand may be made from similar material(s) as the patellar implant 100.

The superior portion 102′ is shown having a convex upper surface andbeing symmetric. The superior portion 102′ is still configured to liftand/or tilt the patellar tendon. The superior portion 102′ is still toreside in proximity to the patellar tendon, while the inferior portion104′ is configured to be placed in proximity to the tibia. The inferiorportion 104′ of the patellar implant 100′ has a convex portion 107. Inparticular, the convex portion 107 is configured to fit the tibia of thepatient. As a result, cutting, grinding, or other altering of the tibiain order to fit the implant 100′ may be avoided. Once in place, thepatellar implant 100′ may be affixed in place through a variety ofmechanisms, described below. The patellar implant 100′ might be affixedto the tibia, the patellar tendon, or both.

Because the superior portion 102′ is configured to elevate and/or tiltthe patellar tendon, the patella may be repositioned. For example, thepatella may be elevated and/or tilted. Consequently, pain and/or otherissues related to patellar-femoral joint problems may be alleviated. Inaddition, because cutting or other alteration of the tibia may beavoided, recovery time and ease of use of the patellar implant 100′ maybe improved.

FIG. 3 depicts another exemplary embodiment of a patellar implant 100″.For clarity, FIG. 3 is not drawn to scale. The components of thepatellar implant 100″ are analogous to the patellar implants 100 and100′. Thus, the components of the patellar implant 100″ are labeledsimilarly. The patellar implant 100″ includes a superior portion 102″,an inferior portion 104″, anterior portion 106″, and posterior portion(not shown in FIG. 3). However, the patellar implant 100″ is wedgeshaped. In particular, lateral surface 108/108′ has been replaced with arounded edge 108″. As for the patellar implants 100 and 100′, the amountof lift and/or tilt of the patellar tendon may vary between patients.Consequently, the size, angles between, degree of rounding, and/orspecific shape of the patellar implant 100″ and portions 102″, 104″,106″, 107″, 108″, 112″, and 114″ may also vary. In addition, thepatellar implant 100″ is used in a similar manner to and made fromsimilar material(s) as the patellar implants 100/100′. The superiorportion 102″ has a convex upper surface and is still configured to liftand/or tilt the patellar tendon. The superior portion 102″ is still toreside in proximity to the patellar tendon, while the inferior portion104″ is configured to be placed in proximity to the tibia. The inferiorportion 104″ has a convex portion 107″ configured to fit the tibia ofthe patient. As a result, cutting, grinding, or other altering of thetibia in order to fit the implant 100″ may be avoided. However, inanother embodiment, the concave portion 107″ may be omitted. Once inplace, the patellar implant 100″ may be affixed in place through avariety of mechanisms, described below. The patellar implant 100″ mightbe affixed to the tibia, the patellar tendon, or both.

Through the use of the patellar implant 100″, the patellar tendon may belifted and/or tilted and the patella repositioned. In addition, thepatellar implant 100″ is wedged shaped. Thus, the lateral surface 110″is wider than the rounded edge 108″. As a result, the patellar implant100″ tends to tilt the patellar tendon toward the rounded edge 108″.Consequently, the ability of the patellar implant 100″ to tilt thepatellar tendon is improved. A greater tilt of the patellar tendon, aswell as the patella, may thus be achieved. Consequently, pain and/orother issues related to patellar-femoral joint problems may bealleviated. Because cutting or other alteration of the tibia may beavoided if the concave portion 107″ is provided, recovery time and easeof use of the patellar implant 100″ may be improved.

FIG. 4 depicts another exemplary embodiment of a patellar implant 100″′.For clarity, both perspective and side views are shown in FIG. 4. Inaddition, FIG. 4 is not drawn to scale. The components of the patellarimplant 100″′ are analogous to the patellar implants 100, 100′, and100″. Thus, the components of the patellar implant 100″′ are labeledsimilarly. The patellar implant 100″′ includes a superior portion 102″′,an inferior portion 104″′, anterior portion 106″′, and posterior portion(not shown in FIG. 4). However, the patellar implant 100″′ is tapered.In particular, lateral surfaces 108″′ and 110″′ are thicker near theanterior portion 106″. As for the patellar implants 100, 100′, and 100″,the amount of lift and/or tilt of the patellar tendon may vary betweenpatients. Consequently, the size, angles between, degree of rounding,and/or specific shape of the patellar implant 100″′ and portions 102″′,104″′, 106″′, 107″, 108″, 110″, 112″′, and 114″′ may also vary. Inaddition, the patellar implant 100″′ is used in a similar manner to andmade from similar material(s) as the patellar implants 100/100′/100″.

The superior portion 102″′ has a convex upper surface and is stillconfigured to lift and/or tilt the patellar tendon. The superior portion102″′ is still to reside in proximity to the patellar tendon, while theinferior portion 104″′ is configured to be placed in proximity to thetibia. The inferior portion 104″′ has a convex portion 107″ configuredto fit the tibia of the patient. As a result, cutting, grinding, orother altering of the tibia in order to fit the implant 100″′ may beavoided. However, in another embodiment, the concave portion 107″ may beomitted. Once in place, the patellar implant 100″′ may be affixed inplace through a variety of mechanisms, described below. The patellarimplant 100″′ might be affixed to the tibia, the patellar tendon, orboth.

In addition, the patellar implant 100″′ is tapered. Thus, the superiorportion 102″′ is higher at the anterior portion 106″′ (nearer to thepatella) than at the posterior portion (closer to the distal attachmentof the patellar tendon). As a result, the elevation and/or tilt providedby the patellar implant 100″′ may place less stress on the patellartendon. Consequently, the comfort and/or usability of the patellarimplant 100″′ may be improved. Thus, the patellar implant 100″′ may beused to tilt and/or lift the patellar tendon and reposition the patella.Consequently, pain and/or other issues related to patellar-femoral jointproblems may be alleviated. Because cutting or other alteration of thetibia may be avoided if the concave portion 107″′ is provided, recoverytime and ease of use of the patellar implant 100″′ may be improved.Further, because the patellar implant 100″′ is tapered, the stress onthe patellar tendon may be reduced.

FIG. 5 depicts another exemplary embodiment of a patellar implant 200.For clarity, FIG. 5 is not drawn to scale. The components of thepatellar implant 200 are analogous to the patellar implants100/100′/100″′. Thus, the components of the patellar implant 200 arelabeled similarly. The patellar implant 200 includes a superior portion202, an inferior portion 204, anterior portion 206, and posteriorportion (not shown in FIG. 5) corresponding to the superior portion102/102′/102″/102″′, inferior portion 104/104′/104″/104″′, and anterior106/106′.106″/106″′. As for the patellar implants 100, 100′. 100″ and or100″′, the amount of lift and/or tilt of the patellar tendon may varybetween patients. Consequently, the size, angles between, degree ofrounding, and/or specific shape of the patellar implant 200 and portions202, 204, 206, 207, 208, 210, 212, and 214 may also vary. In addition,the patellar implant 200 is used in a similar manner to and made fromsimilar material(s) as the patellar implants 100/100′/100″/100″′.

In addition, layers 220, 222, 224 and 226 are shown. In the embodimentshown, the layers 220 and 222 are configured to be added to the superiorportion 204. The layers 224 and 226 are configured to be added to theinferior portion 202. By adding one or more of the layers 220 and 222,the height, h, of the patellar implant 100″ may be increased. Inaddition, note that the layers 220 and 222 do not extend across thewidth, w, of the patellar implant 200. As a result, the layers 220, 222,224, and/or 226 may be used to adjust the tilt to the patellar tendonprovided by the patellar implant 200. The layers 220 and 222 do notextend along the entire length of the patellar implant and/or may betapered. The layers 220 and 222 may be used to alter the height of thepatellar implant 200 along its length. Stated differently, the taper ofthe patellar implant 200 may be configured using the layers 220 and/or222. In another embodiment, the amount each of the layers 220, 222, 224,and/or 226 extend along the height, width, and length of the patellarimplant 200 as well as the location of the layers 220, 222, 224, and/or226 on the patellar implant 200 may be selected. Although not shown,layers that may be added to the anterior portion 206 and/or theposterior portion (not shown) to increase the length of the patellarimplant 200. Consequently, the patellar implant 200 may be configured bythe surgeon or other qualified individual when being prepared for use ina patient.

The superior portion 202 has a convex upper surface, is symmetric, andis still configured to lift and/or tilt the patellar tendon. Thesuperior portion 202 is still to reside in proximity to the patellartendon, while the inferior portion 204 is configured to be placed inproximity to the tibia. The inferior portion 204 has a convex portion207 configured to fit the tibia of the patient. As a result, cutting,grinding, or other altering of the tibia in order to fit the implant100″ may be avoided. Once in place, the patellar implant 200 may beaffixed in place through a variety of mechanisms, described below. Thepatellar implant 200 might be affixed to the tibia, the patellar tendon,or both. In addition, as described above, the height, tilt, and/or taperof the patellar implant 200 may be configured for the needs of aparticular patient. The patellar tendon may be lifted and/or tilted andthe patella repositioned in a desired fashion. Consequently, pain and/orother issues related to patellar-femoral joint problems may bealleviated. Because cutting or other alteration of the tibia may beavoided, recovery time and ease of use of the patellar implant 200 maybe improved. Further, use of the layers 220, 222, 224, and 226 may beused to adjust the elevation and/or tilt provided as well as the fit ofthe patellar implant 200 to the tibia. Consequently, use of the patellarimplant 200 may be improved.

FIG. 6 depicts another exemplary embodiment of a patellar implant 200′.For clarity, FIG. 6 is not drawn to scale. The components of thepatellar implant 200′ are analogous to the patellar implants 200 and100/100′/100″. Thus, the components of the patellar implant 200′ arelabeled similarly. The patellar implant 200′ includes a superior portion202′, an inferior portion 204′, anterior portion 206′, and posteriorportion (not shown in FIG. 6). Also shown are lateral surfaces 108′ and110′ as well as the edges 212′ and 214′. As for the patellar implants100/100′/100″/100″′, the amount of lift and/or tilt of the patellartendon may vary between patients. Consequently, the size, anglesbetween, degree of rounding, and/or specific shape of the patellarimplant 200′ and portions 202′, 204′, 206′, 207′, 208′, 210′, 212′, and214′ may also vary. In addition, the patellar implant 200′ is used in asimilar manner to the patellar implants 100/100′/100″/100″200.

In addition, nested sections 220′, 222′, 224′, 226′, 228, and 230 areshown. In the embodiment shown, the sections 220′ and 222′ areconfigured to be telescoped from the superior portion 204′. The sections224′ and 226′ are configured to be, and shown as, telescoped from theinferior portion 202′. The sections 228 and 230 may be telescoped fromthe anterior portion 206. By telescoping the sections 220′, 222′, 224′,226′, 228, and/or 230, the height and/or length of the patellar implant100″ may be increased. In addition, the sections 220′, 222′, 224′,and/or 226′ might be used to adjust the tilt to the patellar tendonprovided by the patellar implant 200′. The sections 220′ and 222′ do notextend along the entire length of the patellar implant and/or may betapered. The sections 220′ and 222′ may be used to alter the height ofthe patellar implant 200′ along its length. Stated differently, thetaper of the patellar implant 200′ may be configured using the sections220′ and/or 222′. The sections 224′ and 226′ may be used adjust the fitof the patellar implant 200′ to the tibia. The sections 228 and 230 maybe used to alter the length of the patellar implant 200′. In oneembodiment, the amount each of the sections 220′, 222′, 224′, 226′, 228,and/or 230 extend along the height, width, and length of the patellarimplant 200′ may be selected. Consequently, the patellar implant 200′may be configured by the surgeon or other qualified individual whenbeing prepared for use in a patient.

The superior portion 202′ has a convex upper surface, is symmetric, andis still configured to lift and/or tilt the patellar tendon. Thesuperior portion 202′ is still to reside in proximity to the patellartendon, while the inferior portion 204′ is configured to be placed inproximity to the tibia. The inferior portion 204′ has a convex portion207′ configured to fit the tibia of the patient. This fit may beimproved using the sections 224′ and 226′. As a result, cutting,grinding, or other altering of the tibia in order to fit the implant200′ may be avoided. Once in place, the patellar implant 200′ may beaffixed in place through a variety of mechanisms, described below. Thepatellar implant 200′ might be affixed to the tibia, the patellartendon, or both. In addition, as described above, the height, tilt,and/or taper of the patellar implant 200′ may be configured for theneeds of a particular patient. The patellar tendon may be lifted and/ortilted and the patella repositioned in a desired fashion. Consequently,pain and/or other issues related to patellar-femoral joint problems maybe alleviated.

FIG. 7 depicts an exemplary embodiment of one option for placement of anexemplary embodiment of a patellar implant 100. For clarity, FIG. 7 isnot drawn to scale. For simplicity, only the patellar implant 100depicted in FIG. 1 is described. However, in other embodiments, otherpatellar implants including but not limited to the patellar implants100′, 100″, and 100′″ may be used. Also shown in FIG. 5 are the tibia150, femur 152, native-positioned patella 154, elevated-positionedpatella 154′, native-positioned patellar tendon 156, andelevated/tilted-positioned patellar tendon 156′. A patient mayexperience pain and other patellar-femoral joint problems when thepatella tendon 156 and patella 154 are in their native positions. Thepatellar implant 100 is inserted between the patellar tendon 156 and thetibia 150, as well as between the patella 154 and the distal attachment158 of the patellar tendon 156. The position of the patellar implant100, as well as the shape and size of the patellar implant 100 may beselected in order to elevate and/or tilt the patellar tendon 156 in thedesired manner. For example, for a smaller change in elevation, animplant having a lower height may be selected and/or a patellar implant100 may be moved closer to the patella 154 and further from the distalattachment 158. In order to tilt the patellar tendon 156, a wedge shapedpatellar implant, such as the implant 100″′, may be selected and/or thepatellar implant 100 may be placed at a different angle on the tibia 150(e.g. further into or out of the plane of the page in FIG. 5). As aresult, the patellar tendon 156′ is moved to the elevated/tiltedposition. The change in position of the patellar tendon 156′ causes arepositioning of the patella 154′ to the elevated/tilted position. Thus,the patella 156′ may be repositioned in order to alleviate pain or otherpatellar-femoral joint issues.

FIGS. 8-9 depict another exemplary embodiment of a patellar implant 300.For clarity, FIGS. 8-9 are not drawn to scale. The components of thepatellar implant 300 are analogous to the patellar implants 100, 100′,100″, 100′″, 200, and 200′. Thus, the components of the patellar implant300 are labeled similarly. However, for clarity, only a superior portion302, an inferior portion 304, and anterior portion 306 are labeled. Asfor the patellar implants 100, 100′, 100″, 100″′, 200, and 200′ theamount of lift and/or tilt of the patellar tendon may vary betweenpatients. Consequently, the size, angles between, degree of rounding,and/or specific shape of the patellar implant 300 and portions 302, 304,and 306 may also vary. In addition, the patellar implant is used in asimilar manner to and made from similar material(s) as the patellarimplants 200/200′/200″.

The superior portion 302 has a convex upper surface and is stillconfigured to lift and/or tilt the patellar tendon. The superior portion302 is still to reside in proximity to the patellar tendon, while theinferior portion 304 is configured to be placed in proximity to thetibia. The inferior portion 304 has a convex portion (not separatelylabeled) configured to fit the tibia of the patient. As a result,cutting, grinding, or other altering of the tibia in order to fit theimplant 300 may be avoided. However, in another embodiment, the concaveportion may be omitted. Once in place, the patellar implant 100″′ may beaffixed in place through a variety of mechanisms, described below. Thepatellar implant 300 might be affixed to the tibia, the patellar tendon,or both.

Thus, the patellar implant 300 may be used to tilt and/or lift thepatellar tendon and reposition the patella. Consequently, pain and/orother issues related to patellar-femoral joint problems may bealleviated. Because cutting or other alteration of the tibia may beavoided if the concave portion provided, recovery time and ease of useof the patellar implant 300 may be improved.

FIGS. 10-11 depict another exemplary embodiment of a patellar implant400 that includes a mechanism for affixing the patellar implant. Forclarity, FIGS. 10-11 are not drawn to scale. The components of thepatellar implant 400 are analogous to the patellar implants 100, 100′,100″, 100″′, 200, 200′, and 300. Thus, the components of the patellarimplant 300 are labeled similarly. In addition, some components such asthe through holes 408 and 410 are shown. However, for clarity, only asuperior portion 402, an inferior portion 404, anterior portion 406, andthrough holes 408 and 410 are labeled. As for the patellar implants 100,100′, 100″, 100″′, 200, 200′, and 300 the amount of lift and/or tilt ofthe patellar tendon may vary between patients. Consequently, the size,angles between, degree of rounding, and/or specific shape of thepatellar implant 400 and portions 402, 404, 406, 408, and/or 410 mayalso vary. In addition, the patellar implant 400 is used in a similarmanner to and made from similar material(s) as the patellar implants100/100′/100″/100″′/200/200′/300.

The superior portion 402 has a convex upper surface and is stillconfigured to lift and/or tilt the patellar tendon. The superior portion402 is still to reside in proximity to the patellar tendon, while theinferior portion 404 is configured to be placed in proximity to thetibia. The inferior portion 404 has a convex portion (not separatelylabeled) configured to fit the tibia of the patient. As a result,cutting, grinding, or other altering of the tibia in order to fit theimplant 400 may be avoided. However, in another embodiment, the concaveportion may be omitted.

Once in place, the patellar implant 400 may be affixed in place througha variety of mechanisms. In the embodiment shown, through holes 408 and410 may be used to affix the patellar implant 400. The through holes 408and 410 extend through the top portion 402 and the inferior portion 404.In one embodiment, the holes 408 and 410 may be screw holes. In such anembodiment, the patellar implant 400 may be screwed to the tibia. Inanother embodiment, the through holes 408 and 410 might be suture holesused to suture the patellar implant to the patellar tendon. In yetanother embodiment, a mixture of screw holes and suture holes might beused. Thus, the through holes 408 and 410 permit the patellar implant400 to be mounted to various tissue adjacent to the implant's location.

Thus, the patellar implant 400 may be used to tilt and/or lift thepatellar tendon and reposition the patella. Consequently, pain and/orother issues related to patellar-femoral joint problems may bealleviated.

FIG. 12 depicts another exemplary embodiment of a patellar implant 500that includes a mechanism for affixing the patellar implant. Forclarity, FIG. 12 is not drawn to scale. The components of the patellarimplant 500 are analogous to the patellar implants 100, 100′, 100″,100″′, 200, 200′, 300, and 400. Thus, the components of the patellarimplant 500 are labeled similarly. However, for clarity, only a superiorportion 502, an inferior portion 504, anterior portion 506, andaffixation spikes 508 are labeled. As for the patellar implants 100,100′, 100″, 100″′, 200, 200′, 300, and 400 the amount of lift and/ortilt of the patellar tendon may vary between patients. Consequently, thesize, angles between, degree of rounding, and/or specific shape of thepatellar implant 500 and portions 502, 504, 506, and/or 508 may alsovary. In addition, the patellar implant 500 is used in a similar mannerto and made from similar material(s) as the patellar implants100/100′/100″/100″′/200/200′/300/400.

The superior portion 502 has a convex upper surface and is stillconfigured to lift and/or tilt the patellar tendon. The superior portion502 is still to reside in proximity to the patellar tendon, while theinferior portion 504 is configured to be placed in proximity to thetibia. The inferior portion 504 has a convex portion (not separatelylabeled) configured to fit the tibia of the patient. As a result,cutting, grinding, or other altering of the tibia in order to fit theimplant 500 may be avoided. However, in another embodiment, the concaveportion may be omitted.

Once in place, the patellar implant 500 may be affixed in place througha variety of mechanisms. In the embodiment shown, affixation spikes 508may be used to affix the patellar implant 500. The affixation spikes 508may be mounted the patellar implant 500 to adjacent tissue, such asbone. Thus, the patellar implant 500 may be used to tilt and/or lift thepatellar tendon and reposition the patella. Consequently, pain and/orother issues related to patellar-femoral joint problems may bealleviated.

FIG. 13 depicts another exemplary embodiment of a patellar implant 600that includes a mechanism for affixing the patellar implant. Forclarity, FIG. 13 is not drawn to scale. The components of the patellarimplant 600 are analogous to the patellar implants 100, 100′, 100″,100″′, 200, 200′, 300, 400, and 500. Thus, the components of thepatellar implant 600 are labeled similarly. However, for clarity, only asuperior portion 602, an inferior portion 604, anterior portion 606, andbone growth enhancement device 608 are labeled. As for the patellarimplants 100, 100′, 100″, 100′″, 200, 200′, 300, 400, and 500 the amountof lift and/or tilt of the patellar tendon may vary between patients.Consequently, the size, angles between, degree of rounding, and/orspecific shape of the patellar implant 600 and portions 602, 604, 606,and/or 608 may also vary. In addition, the patellar implant 500 is usedin a similar manner to and made from similar material(s) as the patellarimplants 100/100′/100″/100″′/200/200′/300/400/500.

The superior portion 602 has a convex upper surface and is stillconfigured to lift and/or tilt the patellar tendon. The superior portion602 is still to reside in proximity to the patellar tendon, while theinferior portion 604 is configured to be placed in proximity to thetibia. The inferior portion 604 has a convex portion (not separatelylabeled) configured to fit the tibia of the patient. As a result,cutting, grinding, or other altering of the tibia in order to fit theimplant 600 may be avoided. However, in another embodiment, the concaveportion may be omitted.

Once in place, the patellar implant 600 may be affixed in place througha variety of mechanisms. In the embodiment shown, the bone growthenhancement device 608 includes affixation beads 608. The affixationbeads 608 are used to promote growth of bone, such as the tibia, withthe patellar implant 608. Thus, the patellar implant 600 may be affixedin place and used to tilt and/or lift the patellar tendon and repositionthe patella. Consequently, pain and/or other issues related topatellar-femoral joint problems may be alleviated.

FIG. 14-16 depicts other exemplary embodiments of patellar implants 700,710, and 720 positioned beneath a patellar tendon 702, 712, and 722,respectively, and on a tibia 704, 714, and 724, respectively. Forclarity, FIGS. 14-16 are not drawn to scale. Thus, patellar implantswhich have a convex inferior surface 700, which are wedge shaped 710, orwhich are have a flat inferior surface 720 are shown. Thus, the patellartendon 702 may be elevated, the patellar tendon 712 may be elevated andtilted, and the tibia 724 may be processed to provide a flat uppersurface for affixing the patellar implant 722. The patellar implants700, 710, and 720 may be affixed in place and used to tilt and/or liftthe patellar tendon 702, 712, 714 and reposition the patella.Consequently, pain and/or other issues related to patellar-femoral jointproblems may be alleviated.

FIGS. 17-22 depict another exemplary embodiment of a patellar implant750. Front, perspective, side, bottom, top, and rear views are shown inFIGS. 17-22, respectively. For clarity, FIGS. 17-22 are not drawn toscale. The patellar implant 750 is substantially wedge shaped, has aconcave inferior portion, a substantially convex superior portion, andthrough holes. Consequently, the benefits of the patellar implantsdiscussed herein may be achieved.

FIG. 23 depicts an exemplary embodiment of a method 800 for placing apatellar implant, such as a patellar implant described herein. Forsimplicity, the method 800 is described in the context of the patellarimplant 100. The bone is optionally prepared for the implant, via step802. For example, step 802 might include cutting a slot or flat portionin the tibia, for example to be flat as is shown in FIG. 16. However, inother embodiments, preparing the bone may be performed in another manneror may be omitted. The patellar implant 100 is inserted between thepatellar tendon and the tibia, as well as between the patella and thedistal attachment of the patellar tendon to the tibia, via step 804.Step 804 may include providing a surgical incision, for example 2-3 cmin length. In one embodiment, step 804 is performed using minimallyinvasive techniques. Further, the prepatellar fat pad may be removed. Aspart of step 804, arthroscopic evaluation may be performed to assesstracking and assist with intraopertaive decision making.

Step 804 may also include determining the desired tilt and/or elevationfor the patellar implant 100. Although an assessment may have been madeprior to surgery, the final decisions on elevation and tilt, as well assize, shape, placement and other relevant characteristics of thepatellar implant 100 may be made during surgery. Step 802, therefore,may also include selecting and/or adjusting the patellar implant as wellas determining the final placement of the implant 100. For example, thepatellar implant 100 at or near a desired size and shape may be selectedin step 804 In addition, if layers are to be added, sections telescopedor other adjustments made, these adjustments are preferably completed instep 802, prior to the patellar implant 100 being affixed within thepatient. In another embodiment, the configuration of the patellarimplant 100 may still be adjusted at a later time.

Once appropriate elevation and/or tilt of the patella implant 100, andthus the patellar tendon and patella, have been achieved, the patellarimplant 100 may be affixed, via step 804. In one embodiment, thepatellar implant 100 is fixated to the proximal tibia, to the patellartendon, or both. Fixation may be accomplished by using any fixationdevice, including but not limited to those described herein. Forexample, fixation may be achieved using a screw, sutures, nail(s), bonecement or other adhesives, or direct attachment to the patella tendon.

Using the method 800, a patellar implant, such as the implants 100,100′, 100″, 100″, 200, 200′, 400, 500, and/or 600 may be placed in apatient. Consequently, the therapeutic benefits of the implant may beachieved.

A method and system for a patellar implant has been disclosed. Themethod and system have been described in accordance with the embodimentsshown, and one of ordinary skill in the art will readily recognize thatthere could be variations to the embodiments, and any variations wouldbe within the spirit and scope of the present application. Accordingly,many modifications may be made by one of ordinary skill in the artwithout departing from the spirit and scope of the appended claims.

1. A method of decreasing a force applied between two bones of a joint,comprising: inserting an implant between a tendon and a first bone;affixing the implant to the first bone at a location such that thetendon is elevated and tensioned by the implant; allowing movement ofthe tendon over the implant during articulation of the joint; decreasingthe force load applied across the joint.
 2. The method of claim 1,wherein the implant is rigid.
 3. The method of claim 1, wherein theimplant is a single piece.
 4. The method of claim 1, wherein the implantis a two piece implant with a bone contacting portion of a firstmaterial selected for contacting bone and a tendon contacting portionformed of a second material.
 5. The method of claim 4, wherein thesecond material is softer than the first material.
 6. The method ofclaim 1, wherein the implant defines a height from about 0.5 centimetersto about 3 centimeters.
 7. The method of claim 1, wherein affixing theimplant to the first bone comprises screwing the implant to the firstbone.
 8. The method of claim 7, wherein the implant comprises at leastone through hole therein for receiving at least one screw.
 9. A methodof decreasing pain caused by malalignment of the bones of a joint,comprising: inserting an implant between a tendon and a first bone;affixing the implant to the first bone at a location such that thetendon is elevated and repositioned by the implant; allowing movement ofthe tendon over the implant during articulation of the joint; decreasingpain at the joint and improving alignment by reposition the tendon withthe implant.
 10. The method of claim 9, wherein the implant is rigid.11. The method of claim 9, wherein the implant is a single piece. 12.The method of claim 9, wherein the implant is a two piece implant with abone contacting portion of a first material selected for contacting boneand a tendon contacting portion formed of a second material.
 13. Themethod of claim 12, wherein the second material is softer than the firstmaterial.
 14. The method of claim 9, wherein the implant defines aheight from about 0.5 centimeters to about 3 centimeters.
 15. The methodof claim 9, wherein inserting the implant between the tendon and thetibia comprises tilting the tendon to alter tracking of the joint. 16.The method of claim 9, wherein affixing the implant to the first bonecomprises screwing the implant to the first bone.
 17. The method ofclaim 16, wherein the implant comprises at least one through holetherein for receiving at least one screw.
 18. The method of claim 9,wherein inserting the implant between the tendon and the first bonecomprises inserting the implant without removing a portion of the firstbone.
 19. The method of claim 9, wherein an inferior portion of theimplant defines a concave portion configured to fit an outer surface ofthe first bone.
 20. The method of claim 9, wherein a superior portion ifthe implant has a smooth concave surface and allows movement of thetendon over the implant.